Self-cleaning humidifier



pt 1952 A H. BAHNSCN, JR

SELF-CLEANING HUMIDIF'IER 2 SHEETS-SHEET 1 Filed March 16, 1951 Patented Sept. 9, 1952 SELF-CLEANING HUMIDIFIER Agnew-H. Bahnson, .lr., Winston-Salem, N. (L, as-

Signor to Wachovia Bank and Trust 00., Winston-Salem, N. (3., a corporation of North Carolina, as trustee Application March 16, 1951, Serial No. 215,919

17 Claims.

This invention relates to humidifiers and particularly to humidifiers of thetype wherein water is supplied to a rapidly rotating impeller disk from which it is thrown by centrifugal force against a grid ring having a row of stationary blades or teeth circumferentially surrounding the path of the periphery of the disk and thus atomized to be entrained by a stream of air blown past the humidifier.

In known humidifiers of this type, which generally comprise a motor, a motor shaft, a disk mounted on the shaft, a watersupply to the surface of the disk near its axis, a grid ring having an annular row of teeth surrounding the disk and. an imperforate bowl-like casing peripherally surrounding the blades or teeth, certain difficulties have been encountered in the operation of the devices due to thecollection oflint, dirt, etc., on the grid ring. In the case of a humidifier operated in a roomwhereinthere is an appreciable amount of lint in the air, such as in a textile mill, the lint is drawn into the air stream and isdeposited on the rim ofthe casing and on the grid ring where it collects moisture and, due to the passage of the air, extends in the direction of the airstream in elongated tassels or whiskers. Moisture which is deposited on these tassels by the passage of the moistureladen air and/or by drainage from the casing, is blown from: the collected lint in the form. of drops which injure the materials being manufactured. Similar undesirable effects result from the forma- 'tion of drops on the lint which is caught by and collected on the grid ring.

U. S. Patent No. 1,966,872, issued July 17, 11934, discloses ahumidifier structure wherein. the formation of stringy, tassel like deposits of large amounts of lint .or other foreign matter on the rim of the casing is .renderedimpossible. Humidifiers of the general type with which the invention is concerned are disclosed also in U. S.

Patents Nos. 1,544,418 and 1,745,239 to Bahnson.

It is an object of the present invention to provide a humidifier structure which is adapted to prevent the accumulation of lint, and, dirt and the formationoftassels or whiskers on the, gridzring, e. g. the teeth thereof.

It is aiurther objectto provide a self-cleaning humidifier capableof automatically cleaning the t et O ts ri g at all times when not acting in its atomizing capacity. Other objects of the invention include provision of a rotatable grid ring. means for rotating said ring when the humidifier is not in atomizing operation, and means for terminating rotation of the grid ring 4 2 upon commencement of the atomiz-ing operation.

The invention may be 3 described in briefias follows: It consists-of a humidifier havingdriving means, a water supply system, a rotatable impeller disk, and a rotatable grid ring whichis normally stationary. Grid rings ordinarily are mounted to be permanentlystationary, but in the present apparatus, the grid ring is designed for rotation at certain times for cleaning. The apparatus preferably; is designed to impart rotary motion for cleaning of the gridring only during those periods in which the humidifier is-not acting in an atomizing capacity.

The supply of water to humidifiers of the type with which the invention is concerned-normally is intermittent, being controlledin accordance with requirements as established by-therelative humidity of the air being conditioned. the present apparatus, rotation ofthe gridringfor the cleaningoperation is made depend upon the termination of the supply ofwater from its source, and upon commencement of water supply again, the rid ring becomes stationary. A feature ofthe invention comprises means for allowing completion of the cleaning, cycle of the grid ring, after commencement of water supply from the source-but priorto admittance-oi-waterto the surface of therotary impeller disk.

Therefore, inthe normal operation of the ape paratus of the invention, a motor drives, the-im peller disk continuously and the grid ring is driven intermittently, such as through a trans mission from the motorshaft, inclusive of; a clutch.

Means mounted on the grid ring serves also" to clean the deflector or casing when the gridxring rotates.

The invention is illustrated inthe accompany ing drawings, in which:

Fig. 1 is" a front elevation, in part cutaway and in part in" section, showing a humidifier embodying the invention,

Fig. 2 is" a vertical ,axial'section on the line, 2-2 of Fig. I,

Fig; 3 isla side elevation in part in section, of a portion of the. apparatus ofFig. 1,

Fig. 4 is a horizontal axialsection on the-line i -4 through a portion of the apparatus of-Fig. 1,

Fig. 5 is a section on the line 5-5-of Fig, 4, and Fig. 6. is a section taken on the line 6--6 of Fig. 4.

Referring, to the drawings, [0 is a casingtfo'r deflection 'ofan air stream ptwssingtd'thd humidifier, the air streamjdirecti'on being from right to left with respect to the apparatus illustrated which the water flows onto the inner surface of the disk near the axis of the latter. Centrifugal force created by rapid rotation of the disk causes the water to move from the center of the disk to its outer edge and to be thrown from the edge against a grid ring I8 having an annular row of teeth l9 which atomize the water by breaking it 'up into a fine mist or spray which can be carried away by the air stream supplied to the humidifying apparatus.

When the humidifier is in operation, the motor driving the rotary impeller disk may be run continuously, but in accordance with normal procedures water will be supplied to the disk only when the relativehumidity of the air being conditioned falls below the desired value. A main valve controls the supply of water whereby feed to the humidifier can be discontinued when the air under treatment contains the required amount of moisture and can be recommenced when it is necessary to again humidify the air. For the purpose of automatic operation of the main valve '20, it is illustrated in Fig. 1 as being under the control of a humidity responsive device such as any of the well known types of humidistats commonly available.

The grid ring 18 is rotatably mounted and by an arrangement to be presently described, is held stationary while water is being fed to the impeller during atomizing operations, but is rotated by means'of a reduced speed. power transmission when the humidifier is not operating as an atomizer.

The reduced speed power transmission includes a worm gear 2l mounted on the main shaft ll meshing with a gear 22 fixed to a stub shaft 23 journalled in bosses 24 and 25 (carried bya gear box 26 mounted directly behind the gridring I8). The stub shaft 23 carries a worm gear 21 which meshes with a gear '28 of an assembly consisting of the gear 28 keyed to a shaft 29 to which is fixed a smaller gear 30. The smaller gear 30 meshes with a ring gear 3| coaxially surrounding and supported by the main shaft II. It will be seen that when the humidifier is in operation with the main shaft II and rotary impeller disk l3 under continuous drive, the ring gear 3| will be rotating continuously, but at a greatly reduced rate of rotation in accordance with the illustrated gear ratio.

The ring gear 31 is provided with a clutch slot 32 adapted to receive a clutch to be presently described, whereby clutch engagement of the ring gear with the grid ring 18 and rotational drive of the latter is accomplished.

The grid ring l8 includes an annular disk 33, a cam plate 34 fixed thereto, and a clutch ring 35 fixed to the cam plate 34 and having a projecting flange. A cam depression 36 is formed in the cam plate 34, and centered adjacent the depression 36, in the clutch ring, is a clutch slot 31 housing a'clutch 33. V j I The clutch is provided with a'clutch 'pin 39 which projects out through the clutch plate through an elongated slot 31' of smaller area in plan view than the slot 31 in the clutch ring 35 housing the clutch. A spring 40 positioned in the clutch slot 31 of the clutch ring 35 urges the clutch 38, riding in the clutch slot outwardly toward the ring gear 3 I. As the ring gear rotates, the urge of the spring 48 normally is opposed by a clutch control assembly, presently to be described, whereby the clutch is held disengaged from the gear ring. In the absence of opposition by the clutch control assembly to the urge of the spring 40, the spring forces the clutch outward against the inner face of the gear ring, and the outer end of the clutch rides against said face as the gear ring rotates, whereby when the gear ring reaches the proper position to bring its clutch slot 32 in alignment with the clutch slot 31 of the clutch ring, the clutch becomes engaged by reason of its outer end moving into the clutch slot of the gear ring. Engagement of the clutch results in rotation of the grid ring, inclusive of course, of its clutch ring, cam plate, annular disk, and teeth.

Disengagement of the clutch is accomplished by means of the clutch control assembly which is stationary relative to the rotating grid ring. The clutch control assembly includes a clutch disengaging linkage having a cam follower 41 which has a projection 42 adapted to cam against the periphery of the cam plate 34 except when the cam plate presents its cam depression 36.

The clutch disengaging linkage also has a lever arm 43 adapted to move the cam follower 4| under influence from a floating pin 64.

As shown more clearly in Figs. 4-6 the clutch being in the engaged position, the clutch pin cams against the face of the cam follower as the former during its rotation reaches the position of the latter. If the cam follower 4! is not under influence (to the left in Fig. 4) of the lever arm 43 (the latter being under no influence from the floating pin M) the cam follower is free to move to the right against the camming action of the clutch pin whereby disengagement of the clutch is not accomplished, and the cam follower normally is urged to the right (Fig. 4) by the springs 15 and 6 whereby in the absence of force from the lever arm 43 the cam follower remains clear of forceful contact with the clutch pin 39.

It will be clear that when opposite conditions exist, that is when forcing movement of the floating pin 44 to the left (Fig. 4) occurs, responsive to a pressure responsive device presently to be described, the floating pin 44 will move the lever arm 43 and consequently the cam follower H to the left. Under these conditions, the cam follower, or rather its projection, will ride hard against the periphery of the rotating cam plate 34 until the cam plate reaches the position at which the cam follower enters the cam depression 36 under the urging of the lever arm 43 and against the opposition of the springs 45 and 46. When cam follower'4l moves into the cam depression 36, continued rotation of the grid ring l8 causes camming action between the cam follower M and the clutch pin 39 whereby the clutch member 38 is moved to the left in its slot 31 in the clutch ring 35 against the opposition of the clutch spring Ml, becoming disengaged from the gear 3| by reason of withdrawal of its outer end from the clutch slot 32 in the ring gear. Upon disengagement of the clutch, the grid ring 18 becomes stationary, the ring gear continuing to rotate as long as the main shaft l I continues to receive power. Further movement of the grid ring after disengagement of the clutch is prevented by the projection 42 of the cam follower il. Obviously, with the clutch engaged, disengaging impulses applied to the clutch disengaging assembly are ineffective to disengage the-clutch at all times except when the grid ring rotates to the position necessary to bring the cam depression and clutch pin 39 into alignment opposite the fixed position of the' cam follower. once rotation of the grid ring has been commenced, a complete revolution will be had before the clutch is brought back to its point of origin, regardless of the disengaging impulses applied to the cam follower.

Clutch disengaging impulses originate in a pressure responsive secondary valve device I4. The latter includes a valve chamber I4 in the water supply line on the discharge side of the main control valve 263, a resilient diaphragm 4? constituting one end wall of chamber I 4', a valve stem 4'18 secured to diaphragm 4'! for controlling flow of water through the valve, and a spring 59 urging the left end of the valve stem into clos ing position upon its seat in the absence of water pressurein chamber 14'. The right end 43' of the valve stem extends through the valvecasing for actuating a pivotally mounted clutch control lever M.

It will be clear from Fig. 1 that when the main valve 2%} is opened to a source/of water under pressure, the water will enter the valve chamber I l through the inlet feed line I5, and with the valve I l closed (as illustrated in Fig. l) the water pressure will tend to cause outward flexing of the diaphragm M with resultant opening of the valve by movement of the valve stem 48 to the right (Fig. l) and consequently supply water through the outlet line Iii to the rotary impeller disk. Movement of the valve stem end 48 would result in actuation of the clutch control assem bly, the first member of which is the lever BI against one end of which the end '33 of the valve stem bears in opposition to the floating pin 4d, the outer end of which rides against the opposite end of the lever iii. In the condition of the ap paratus illustrated in Fig. l, the clutch being in alignment with the cam follower, admission of water to Valve chamber I l therefore would result' in disengagement of the clutch under the influence of the cam follower responsive to movement of the lever 5|, in turn responsive to movement (to the right in Fig. 1) of the diaphragm and the valve stem. Accordingly, the rotation of the grid ring would be halted and simultaneously water would be supplied to the rotaryimpeller disk, placing the humidifier in atomizing operation.

Atomizing operation for a period sufficient to satisfy the humidity requirements of the air being treated would then result in closing of the main valve 29 by the humidity responsive Valve operator, whereupon termination of water pressure in the chamber I4 and the influence of the spring 50 would cause return of the diaphragm toits normal position as illustrated in Fig. 1

with consequent closing of the valve I4 and termination of the atomizing phase of the operating cycle of the humidifier. The main shaft II still rotates however under drive from the motor I2 and the cleaning phase of the operating cycle would now commence. Since the valve stem end 48' would then be in its left-most position (Fig. 1), lever 5i would be free to move to the position of Fig. 1 under influence from the cam follower springs 45 and 45. Consequently when continued rotation of the ring gear 3| resulted in alignment of its clutch slot 32 with the clutch slot 31 of the clutch ring 35 attached to the stationary grid ring, the clutch 38 would be For this reason,

moved into engagement under. the force of its spring 40 and rotation of the grid ring IE-would begin. I

Mounted upon the stationary casing III-lea grid cleaning devicewhich in the embodiment illustrated in Figs. 1 and 2 comprises a brush 52 which bears against the grid teeth I9. As 'the grid ring I8. rotates during the cleaning phase, brushliz servesto sweep and clean the teeth" of the: grid ring as the grid ring moves past-the brush. A. second brush 53, mounted on the periphery of the grid ring'bears against and serves to clean the lip of the stationary casing as the grid ring and brush rotate within the casing.

The cleaning phaseof the humidifier, i. e. relative motion between the brush 52 and grid teeth I9 would' then continue until thehumidity responsive valve 20 reopened'due to the drop in humidity of the space to be controlled whereupon water would thenagain be admitted to valve chamber I4. However due to the interlocking action between the valve stem ddand the clutch mechanism, conversion of the water pressure applied to diaphragm 41 into movement of valve stem 48 to the right from the positionshown in Fig. 1 to thereby open the valve and permit water to flow through outlet pipe I 5 to theimpeller I3 for producing the humidifying spray cannot take place until the rotating ring gear 3i and thegrid ring assembly have as previously explained moved into the one position where the clutch is disengageable. When such position is reached the valve stem end 58" is'free to move pivoted clutch lever 5| clockwise causing rod 44 to shift to the left and disengage the clutch thus bringing the grid ring to rest and simultaneously opening-the valve to admit water to the impeller to thereby recommence the humidiiying phase. I

In conclusion it is to be understoodthat while the illustrated embodiment is to be "preferred, various minor changes in the construction and arrangement of component parts thereof may be made without however departing from the spirit and'scope of the invention as defined'in the appended claims. 7

I claim:

1'. A self-cleaning humidifier comprising an impeller for distributing water delivered thereto, a gridring member disposed adjacent said impeller for peller, cleaning means cooperative with said grid ring member, means mounting said grid-ringand cleaning means for relative rotation, humidity controlled means eifecting periodic delivery of water to said impeller, and means effecting relative rotation between said grid ring and cleaning means in the intervals between successive" delivery periods ofwater to said impeller;

2. A self-cleaning humidifier comprisingan impeller for distributing. water delivered thereto, a grid ring disposed adjacent said impeller for atomizing water distributed by said impeller, a stationary cleaning means cooperative with said grid ring, humidity controlled means effecting periodic delivery of water to said impeller, and means effecting rotation of said grid ring ill the interval between successive delivery periods of water to said impeller.

3. A self-cleaning humidifier comprising an impeller for distributing water delivered thereto, a grid ring member disposed adjacent said impeller for atomizing water distributed by said impeller, cleaning means cooperative with said grid ring member, means for rotating said impeller continuously during operation of said atomizing water distributed-by saidvim humidifier, means mounting said grid ring and cleaning means for relative rotation, humidity controlled means for delivering water periodically to said impeller, and means effecting relative rotation between said grid ring and cleaning tween successive delivery periods of water, to said impeller. V

5. A self-cleaning humidifier comprising a motor, an impeller secured to the drive shaft of said motor for distributing water delivered under pressure to said impeller, a grid ring member disposed adjacent said impeller for atomizing water distributed by said impeller, a cleaning member cooperative with said grid ring member, one of said members being stationary and the other rotatable, and clutch means for coupling the rotatable one of said members to said drive shaft. 7

6. A self-cleaning humidifier as defined in claim wherein said grid ring member is rotatable and said cleaning member is stationary.

7. A self-cleaning humidifier as defined in claim 5 wherein said cleaning member is stationary, said grid ring member is rotatable, and further including means limiting operation of said clutch means to a predetermined position of said grid ring member. 8. A self-cleaning humidifier comprising a motor, an impeller secured to the drive shaft of said motor for distributing water delivered to said impeller, a grid ring member disposed adjacent said impeller for atomizing water distributed by said impeller, a cleaning member cooperative with said grid ring member, one of said members being stationary and the other rotatable, a power take off from said drive shaft including a speed reducing transmission, and clutch means for coupling the rotatable one of said members to the output of said transmission.

9. A self-cleaning humidifier comprising an impeller member for distributing water delivered thereto, a grid ring member disposed adjacent said impeller member for atomizing water distributed by said impeller member, a stationary cleaning device cooperative with said grid ring member, a motor common to both of said members for rotating the same, said impeller'member being coupled continuously to said motor, clutch means interposed between said motor and grid ring member, and means responsive to the pressure of said water for controlling said clutch means.

' 10. A self-cleaning humidifier as defined in claim 9 wherein said water pressure responsive control means is comprised of a valve through which said water is delivered to said impeller member, a valve operator responsive to said water pressure, and means controlling said clutch means in accordance with the position of said valve operator.

11. A self-cleaning humidifier as defined in claim 9 wherein said water pressure responsive control means is comprised of a valve through '8 which said water is delivered to said impeller member, said valve including a diaphragm responsive to the water pressure and a valve stem actuated by said diaphragm, and means controlling said clutch means in accordance with the position of said valve stem.

12. A self-cleaning humidifier comprising an impeller for distributing water delivered thereto under pressure, a grid ring member disposed adjacent said impeller ior atomizing water distributed by said impeller, a cleaning member cooperative with said grid ring member, one of said members being stationary and the other rotatable, a motor for driving said impeller, a clutch means interposed between said motor and the rotatable one of said members, valve means normally closed but openable under pressure of said water for controlling delivery of said water to said impeller, and means controlling operation of said clutch means in accordance with the operation of said valve means to effect engagement of said clutch means when said valve means is closed and disengagement thereof when said valve means is opened.

13. A self-cleaning humidifier comprising an impeller for distributing water delivered thereto, a grid ring member disposed adjacent said impeller for atomizing water distributed by said impeller, a cleaning member cooperative with said grid ring member one of said members being stationary and the other rotatable, said impeller being coupled to said motor continuously during operation of said humidifier, humidity controlled means for delivering water periodically to said impeller, clutch means interposed between said motor and the rotatable one of said members, and means actuating said clutch means to couple said rotatable member to said motor during the intervals between successive delivery periods of water to said impeller.

14. A self-cleaning humidifier comprising a motor, an impeller driven by said motor for distributing water delivered thereto, a rotatable grid ring disposed adjacent said impeller and mounted coaxially therewith for atomizing water distributed by said impeller, a stationary cleaning device cooperative with said grid ring, a cam plate and clutch ring secured to and mounted coaxially with said grid ring, said cam plate having a depression in the periphery thereof and said clutch ring having a clutch member aligned with said depression and movable radially of said ring, a rin gear driven by said motor, said ring gear being arranged coaxially with said clutch ring and including a slot for receiving said clutch member thereby to couple said gear and ring, and a cam follower cooperative with the periphery of said cam plate and adapted to actuate said clutch member.

15. A self-cleaning humidifier as defined in claim 14 and which further includes valve means responsive to water pressure for controlling delivery of water to said impeller, and means link+ ing said valve means to said cam follower for actuation of the latter by the former.

16. A- self-cleaning humidifier comprising an impeller for distributing water delivered thereto, a grid ring member disposed adjacent said impeller for atomizing water distributed by said impeller, cleaning means cooperative with said grid ring member, means mounting said grid ring and cleaning means for relative rotation, humidity controlled means effecting periodic delivery of water'to said impeller, and means eicontrolled means effecting periodic delivery of 10 water to said impeller, and means effecting relative rotation periodically between said grid ring and cleaning means.

AGNEW H. BAHNSON, Js.

REFERENCES crrnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 969,854 Fries Sept. 13, 1910 1,072,031 Rankine et al Sept. 2, 1913 1,139,385 Theisen May 11, 1915 1,798,822 Wagner Mar. 31, 1931 

